<?php
/**
 * CMysqlColumnSchema class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright 2008-2013 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CMysqlColumnSchema class describes the column meta data of a MySQL table.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.schema.mysql
 * @since 1.0
 */
class CMysqlColumnSchema extends CDbColumnSchema
{
    /**
     * Extracts the PHP type from DB type.
     * @param string $dbType DB type
     */
    protected function extractType($dbType)
    {
        if (strncmp($dbType, 'enum', 4) === 0)
            $this->type = 'string';
        elseif (strpos($dbType, 'float') !== false || strpos($dbType, 'double') !== false)
            $this->type = 'double';
        elseif (strpos($dbType, 'bool') !== false)
            $this->type = 'boolean';
        elseif (strpos($dbType, 'int') === 0 && strpos($dbType, 'unsigned') === false || preg_match('/(bit|tinyint|smallint|mediumint)/', $dbType))
            $this->type = 'integer';
        else
            $this->type = 'string';
    }

    /**
     * Extracts the default value for the column.
     * The value is typecasted to correct PHP type.
     * @param mixed $defaultValue the default value obtained from metadata
     */
    protected function extractDefault($defaultValue)
    {
        if (strncmp($this->dbType, 'bit', 3) === 0)
            $this->defaultValue = bindec(trim($defaultValue, 'b\''));
        elseif ($this->dbType === 'timestamp' && $defaultValue === 'CURRENT_TIMESTAMP')
            $this->defaultValue = null;
        else
            parent::extractDefault($defaultValue);
    }

    /**
     * Extracts size, precision and scale information from column's DB type.
     * @param string $dbType the column's DB type
     */
    protected function extractLimit($dbType)
    {
        if (strncmp($dbType, 'enum', 4) === 0 && preg_match('/\(([\'"])(.*)\\1\)/', $dbType, $matches)) {
            // explode by (single or double) quote and comma (ENUM values may contain commas)
            $values = explode($matches[1] . ',' . $matches[1], $matches[2]);
            $size = 0;
            foreach ($values as $value) {
                if (($n = strlen($value)) > $size)
                    $size = $n;
            }
            $this->size = $this->precision = $size;
        } else
            parent::extractLimit($dbType);
    }
}
